Brifit BT thermometers not picked up by HA - Why?

I’ve a couple of Brifit bluetooth thermometers that should be compatible with HA. The BT hardware is picking them up as I can see them listed in known_devices.yaml under the heading Thermobeacon. HA has a Thermobeacon integration but when I select this it says no devices have been found on the network.

Am I missing something?

No one? Just one of those unknown glitches?